STEP-UP DC DC CONVERTER FOR WHITE LED BACK LIGHT - RICOH R1203x Series Owner's Manual, Data Sheet
Summary
The R1203x series is a high-efficiency, PWM control step-up DC/DC converter IC specifically designed for driving constant current White LED backlights in portable equipment. This manual provides comprehensive technical documentation, including the electrical characteristics, pin configurations (DFN1616-6B and SOT-23-6), and detailed application guides necessary to integrate the chip. It covers features such as adjustable LED dimming via PWM input signals and robust protection circuits like UVLO and OVP. This product is essential for electronics designers developing low-voltage, high-brightness white LED lighting solutions.
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R1203x SERIES
STEP-UP DC/DC CONVERTER FOR WHITE LED BACK LIGHT
NO.EA-271-111123
OUTLINE The R1203x Series are PWM control type step-up DC/DC converter ICs with low supply current. The R1203x is fully dedicated to drive White LEDs with constant current. Each of these ICs consists of an NMOS FET, an oscillator, a PWM comparator, a voltage reference unit, an error amplifier, a current limit circuit, an under voltage lockout circuit (UVLO), and an over-voltage protection circuit (OVP). The R1203x can drive white LEDs in constant current with high efficiency by using an inductor, a diode , a resistor and capacitors as external components. The LEDs current can be set by an external resistance value and can adjust the dimming of LEDs by CE pin according to the signal of PWM. Feedback voltage is 0.2V, therefore power loss by current setting resistance is small and efficiency is good. Maximum duty cycle is internally fixed, Typ. 91%. LEDs can be driven from low voltage. Protection circuits are the current limit of Lx peak current, the over voltage limit of output, and the under voltage lockout function. It is controllable the dimming of LEDs quickly when the PWM signal (between 200Hz to 300k Hz) input to CE pin. If the CE pin input is "L" in the fixed time (Typ. 0.5ms), the IC becomes the standby mode and turns OFF LEDs.
FEATURES • Supply Current ...........................................................Typ. 500μA • Standby Current .........................................................Max. 5μA • Input Voltage Range ..................................................1.8V to 5.5V • Feedback Voltage ......................................................0.2V • Feedback Voltage Accuracy.......................................±1.0% (±10m V) • Temperature-Drift Coefficient of Feedback Voltage ...±150ppm/°C • Oscillator Frequency ..................................................Typ. 1.2MHz • Maximum Duty Cycle .................................................Typ. 91% • Switch ON Resistance ...............................................Typ. 1.35Ω • UVLO Detector Threshold..........................................Typ. 1.6V • Lx Current Limit Protection ........................................Typ. 700m A • OVP Detector Threshold............................................Typ. 29.5V • Switching Control .......................................................PWM • LED dimming control..................................................by external PWM signal (Frequency 200Hz to 300k Hz) • Packages ...................................................................DFN1616-6B, SOT-23-6 • Ceramic capacitors are recommended......................0.22μF
APPLICATION • White LED Backlight for portable equipment
Page Summary Contents For STEP-UP DC DC CONVERTER FOR WHITE LED BACK LIGHT - RICOH R1203x Series Owner's Manual, Data Sheet
Manual Details
| Brand | Ricoh |
|---|---|
| Pages | 13 |
| File Size | 510.85 KB |
| Published | May 31, 2026 |
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Frequently Asked Questions
What is the purpose of the R1203x IC?
The R1203x is a PWM control type step-up DC/DC converter dedicated to driving white LEDs with constant current.
How can I adjust the LED dimming?
You can adjust the dimming using an external PWM signal (Frequency 200Hz to 300kHz) input to the CE pin.
What is the recommended capacitor value?
The manual recommends using ceramic capacitors with a value of 0.22μF.
Will the IC function if I use low voltage?
Yes, LEDs can be driven from low voltage, and the input voltage range is 1.8V to 5.5V.